ABSTRACT This application is a request for continuation of support for a pre-doctoral training program in Microbial Pathogenesis at Yale University. The program is overseen by a Director, Dr. Jorge Galn, and an executive committee of 5 Faculty members. The administrative entity of this training program is housed in the Department of Microbial Pathogenesis at the Yale School of Medicine. Forty-four faculty members from departments of the Yale Medical School and the Faculty of Arts and Sciences representing a cross-section of the microbial pathogenesis research community at Yale are involved in the program as trainers. The training Faculty carry out research in a broad range of topics that are directly relevant to microbial pathogenesis giving students unique opportunities to explore different aspects microbial pathogenesis research. Trainees are also provided with multiple opportunities for scientific interactions not only within their home Departments but also throughout Yale University. The goal of this program is to train students in multidisciplinary approaches to the study of microbial pathogenesis. The training faculty shares the view that the understanding of the biology of pathogenic microorganisms requires experimental approaches and concepts from different fields of science. Therefore the program seeks to provide students with the necessary broad experimental skills and knowledge that will prepare them for a future research career in the study of microbial pathogens. The existence of very strong basic science departments committed to this concept creates a unique environment in which this training program can flourish and produce superbly trained scientists. The training program has been strengthened by the addition of several new Faculty trainers and courses to cover emerging critical areas of microbial pathogenesis research. The expansion of the Microbial Science Institute at the newly developed Yale University's West Campus has enhanced the training opportunities for the students enlisted to this program. The training program consists of formal course work and laboratory rotations during the first two years. This provides a solid and broad conceptual foundation and knowledge base as well as broad experimental training through the laboratory rotations. Students select a research advisor during the second year and prepare and defend a research proposal that will serve as the foundation for the dissertation research project. A Thesis committee monitors the student progress throughout the thesis research process and, finally, the preparation of the dissertation. An External Advisory Board composed of highly accomplished scientists in the field of Microbial Pathogenesis has been appointed to monitor the progress of this training program. Students enter the program through the Combined Program in Biological and Biomedical Sciences (BBS). The BBS unites the more than 250 faculty in basic biological and biomedical sciences at the Yale Medical School, Science Hill on the main University Campus, and the newly developed West Campus. Admission is granted to students with outstanding academic record with particular attention to research experience. The training Faculty is strongly committed to a diverse student body, reflected in the historic success of this program in the recruitment of students from under represented minorities. A robust program to facilitate these recruitment efforts is in place, facilitated by strong institutional commitment to increase diversity both in the student body and the Faculty at Yale University. Given the quality and depth of our pool of applicants, and the expansion of the training opportunities, we request funds to support 4 graduate students in years 2 and 3 (8 slots) for a five-year period.